Neuroprotective effect of Spilanthes acmella Murr. on pesticide-induced neuronal cells death

Objective: To investigate protective effects of Spilanthes acmella(S,acmella) Murr,extracts against pesticide-induced neuronal cells death and to elucidate the underlying molecular mechanism in dopaminergic(SH-SY5Y) cells lines,Methods: Cell viability of SH-SY5 Y cells was studied by treating the cells with various concentration of pirimicarb for 24 hr,Neuroprotective effect of S,acmella Murr,extracts was investigated by adding the plant extracts to the medium for 24 hr prior to the incubation with 100 μM H_2O_2 or with pirimicarb for 24 hr,Control-untreated cells were incubated with the culture medium,Cell viability was measured by MTT assay,calpain and calpastatin expressions were analyzed by Western blotting and immunocytochemistry,Results: Pretreatment of SH-SY5 Y cells with S,acmella Murr,extracts(1 μg/m L) for 24 hr significantly increased the dopaminergic neurons in pirimicarb-induced neurotoxicity,In addition,pretreatment with the S,acmella Murr,extracts led to decreased calpain but increased calpastatin protein levels,Conclusion: S,acmella Murr,extracts exerted neuroprotective effect,via an alteration of calcium homeostasis,against pirimicarb induced neurotoxicity,The S,acmella Murr,might be a potential natural candidate with neuroprotective activity.

Attenuation of oxidative stress-induced neuronal cell death by Hydnophytum formicar-um Jack.

Objective: To investigate protective effects of Hydnophytum formicarum Jack.(H. formicarum) extracts via regulation of SIRT1-FOXO3a-ADAM10 signaling and antioxidant activity against H_2O_2-induced neurotoxicity in neuroblastoma SH-SY5Y cells. Methods: Cell viability and apoptosis of neuronal cells pretreated with H. formicarum Jack. extracts under oxidative stress were determined by MTT assay and flow cytometry. The intracellular reactive oxygen species(ROS) was performed using Carboxy-DCFDA assay. Additionally, a profile of protein expressions related to neuroprotection was detected by western blot analysis. Results: The plant extracts(methanol and ethyl acetate) elicited protective effects on the neuronal cell death as performed by the MTT assay and by apoptosis analysis via the activation of BCL-2. Both ethyl acetate and methanol extracts exerted inhibitory effects against H_2O_2-induced ROS generation in the SH-SY5Y cells. Furthermore, the possible mechanism of neuroprotection of H. formicarum Jack. was observed through its antioxidant properties by maintaining the levels of catalase and SOD2 proteins as well as activating SIRT1-FOXO3a pathway. Importantly, pretreatment of neuronal cells with H. formicarum Jack. significantly recovered the levels of ADAM10 protein compared with the H_2O_2 treatment alone. Conclusions: The recent findings suggest the protective effects of H. formicarum Jack. plant extracts on attenuating H_2O_2-induced neurotoxicity in human SH-SY5Y cells.

Substrate specificity of avian influenza H5N1 neuraminidase

AIM: To characterise neuraminidase(NA) substrate specificity of avian influenza H5N1 strains from humans and birds comparing to seasonal influenza virus.METHODS: Avian influenza H5N1 strains from humans and birds were recruited for characterising their NA substrate specificity by using a modified commercial fluorescence Amplex Red assay. This method can identify the preference of α2,6-linked sialic acid or α2,3-linked sialic acid. Moreover, to avoid the bias of input virus, reverse genetic virus using NA gene from human isolated H5N1 were generated and used to compare with the seasonal influenza virus. Lastly, the substrate specificity profile was further confirmed by high-performance liquid chromatography(HPLC) analysis of the enzymatic product. RESULTS: The H5N1 NA showed higher activity on α2,3-linked sialic acid than α2,6-linked(P < 0.0001). To compare the NA activity between the H5N1 and seasonal influenza viruses, reverse genetic viruses carrying the NA of H5N1 viruses and NA from a seasonal H3N2 virus was generated. In these reverse genetic viruses, the NA activity of the H5N1 showed markedly higher activity against α2,3-linked sialic acid than that of the H3N2 virus, whereas the activities on α2,6-linkage were comparable. Interestingly, NA from an H5N1 human isolate that was previously shown to have heamagglutinin(HA) with dual specificity showed reduced activity on α2,3-linkage. To confirm the substrate specificity profile, HPLC analytic of enzymatic product was performed. Similar to Amplex red assay, H5N1 virus showed abundant preference on α2,3-linked sialic acid.CONCLUSION: H5N1 virus maintains the avian specific NA and NA changes may be needed to accompany changes in HA receptor preference for the viral adaptation to humans.

Development of personal protective equipment for the COVID-19 pandemic in Thailand and technical aspects of testing gown materials

During the coronavirus disease 2019(COVID-19)pandemic in early 2020,Thailand,like many other countries around the world,experienced a lack of personal protective equipment(PPE)for frontline medical staff.This was not only due to the scarcity of PPE,but also because some of the available PPE did not meet the standard to properly protect frontline medical staff from the virus.During that time,the industrial sector worked closely with academic and governmental sectors to develop and produce appropriate isolation gowns,coveralls and masks.

Tungstophosphoric acid catalyzed synthesis of N-sulfonyl-1,2,3,4-tetrahydroisoquinoline analogs

An operationally simple and eco-friendly protocol has been developed for the synthesis of N-sulfonyl- 1,2,3,4-tetrahydroisoquinolines 3 using the modified Pictet-Spengler reaction of N-sulfonylphenylethy- lamines 1 and various aldehydes 2 in the presence of tungstophosphoric acid hydrate.